Considering the following reaction, find the equivalent weight of chlorine, given that molar mass of ${\mathrm{Cl}}_2$ is M. ${\mathrm{Cl}}_2+\mathrm{NaOH}\to \mathrm{NaCl}+{\mathrm{NaClO}}_3+{\mathrm{H}}_2\mathrm{O}$

Considering half oxidation and half reduction reaction: 

Oxidation: 

$6{\mathrm{OH}}^{-}+\frac{1}{2}{\mathrm{Cl}}_2\to 2{\mathrm{ClO}}_3^{-}+3{\mathrm{H}}_2\mathrm{O}+5{\mathrm{e}}^{-}$

Reduction: $\frac{5}{2}{\mathrm{Cl}}_2+5{\mathrm{e}}^{-}\to 5{\mathrm{Cl}}^{-}$

3 moles of Cl₂ and 5 moles of electrons are involved in the redox reaction 

$\text{ equivalent mass =}\frac{ \mathrm{molecularmass} }{\mathrm{n} \mathrm{factor} }=\frac{3}{5}\mathrm{M}$